“As the first prolonged half-life therapies, ELOCTATE and ALPROLIX have
shown low rates in both joint bleeding and overall annualized bleeding
episodes,” said Kate Dawson M.D., vice president, U.S. Medical at
Biogen. “Their ability to reduce bleed rates, which may translate into
the potential for reducing some joint disease, continues to reaffirm
their clinical value for people living with hemophilia A and B.”

For people with severe hemophilia A and B, most bleeding events occur in
joints. When bleeding events occur repeatedly in the same joint (known
as a target joint), it is often a precursor to chronic joint disease,
marked by progressive deterioration of the joint.1 These
post-hoc analyses aimed to assess the frequency of bleeding events and
the dosing of ELOCTATE and ALPROLIX in study participants who had one or
more target joint bleeds [major joint (e.g., knee, elbow, ankle) with
three or more bleeding episodes in a three-month (hemophilia B) or
six-month (hemophilia A) period].2,3

“Understanding the impact of ELOCTATE and ALPROLIX on people with target
joint bleeds provides further insight into their value in a real-world
setting,” said Birgitte Volck, M.D., Ph.D., senior vice president of
Development and chief medical officer of Sobi. “These new results from
the post hoc analyses highlight the value of extended half-life therapy
in managing and controlling bleeds, adding to the body of robust
clinical data and the longest real-world experience of any extended
half-life therapy to date."

Results Highlight Therapies’ Potential for Reducing Bleed Rates in
Target JointsIn this ASPIRE (an ongoing extension of Phase 3
pivotal trials A-LONG and Kids A-LONG) post-hoc analysis, for people
with hemophilia A taking ELOCTATE prophylactically, on-study annualized
bleeding rates (ABRs) overall and in target joints were lower than
pre-study bleeding rates. Data from ASPIRE showed that nearly half of
the adult and adolescent participants in the weekly prophylaxis,
individualized prophylaxis and modified prophylaxis arms (n=26, n=82,
n=12, respectively) did not have any target joint bleeds (42.3, 47.6 and
41.7 percent, respectively). For children, 53.8 percent of participants
in the individualized prophylaxis group (n=13) did not have any target
joint bleeding episodes. In addition, nearly all (97.4 percent) target
joints in adult and adolescent participants taking ELOCTATE were
resolved during the follow-up period, suggesting that the therapy may be
equally effective for preventing target joint bleeding episodes in
weight-bearing and non-weight-bearing joints. The median dosing
intervals for ASPIRE participants with target joints at baseline were
similar to those for the A-LONG and Kids A-LONG overall population.2

In the B-LONG (the pivotal Phase 3 study) post-hoc analysis, for people
with hemophilia B taking ALPROLIX prophylactically, the therapy was
shown effective in reducing the frequency of bleeding episodes overall
and in target joints. The analysis found that 48.6 percent of
participants receiving weekly prophylaxis (n=35) and 37.5 percent of
participants on individualized interval prophylaxis (n=8) did not have
any target joint bleeds at the end of B-LONG. Overall, participants’
target joint, spontaneous target joint and traumatic target joint median
ABRs were low for participants in the weekly prophylaxis arm (1.03, 0.00
and 0.00 respectively) and the individualized interval prophylaxis arm
(2.20, 2.20 and 0.00 respectively). Additionally, among B-LONG
participants entering the trial with target joints (n=43), the on-study
median dosing intervals were longer (6.98 days in the weekly prophylaxis
arm and 10.25 in the individualized interval prophylaxis arm) than the
pre-study dosing interval with a traditional factor therapy, suggesting
that target joint bleeds may be effectively managed and controlled with
an extended prophylactic dosing regimen.3

About Hemophilia A and BHemophilia is a rare, genetic
disorder in which the ability of a person’s blood to clot is impaired.
Hemophilia A occurs in about one in 5,000 male births annually, and more
rarely in females. Hemophilia B occurs in about one in 25,000 male
births annually, and more rarely in females. Worldwide, it is estimated
that more than 400,000 people are living with hemophilia. Hemophilia A
is caused by having substantially reduced or no factor VIII activity,
while hemophilia B is caused by having substantially reduced or no
factor IX activity; factor VIII and factor IX are needed for normal
blood clotting.

People with hemophilia A or B experience prolonged bleeding episodes
that can cause pain, irreversible joint damage and life-threatening
hemorrhages. Prophylactic infusions of factor VIII or IX can temporarily
replace the missing clotting factors that are needed to control bleeding
and prevent new bleeding episodes.4 The Medical and
Scientific Advisory Council of the National Hemophilia Foundation
recommends prophylaxis as the optimal therapy for people with severe
hemophilia A or B.5

About ELOCTATE/ELOCTAELOCTATE® [Antihemophilic
Factor (Recombinant), Fc Fusion Protein], the first recombinant clotting
factor VIII therapy with prolonged circulation in the body, is approved
in the United States, Canada, Australia and Japan. In the European
Union, it was recently approved and marketed under the trade name ELOCTA®.
It is indicated in the United States for the control and prevention of
bleeding episodes, perioperative (surgical) management and routine
prophylaxis in adults and children with hemophilia A. ELOCTATE is not
indicated for the treatment of a bleeding disorder called von Willebrand
disease. ELOCTATE was developed by fusing B-domain deleted factor VIII
to the Fc portion of immunoglobulin G subclass 1, or IgG1 (a
protein commonly found in the body). It is believed that this enables
ELOCTATE to use a naturally occurring pathway to prolong the time the
therapy remains in the body.

Common adverse reactions (incidence of greater than or equal to 1
percent) reported in the registrational A-LONG study were arthralgia
(joint pain) and malaise (general discomfort). For important safety
information, and the United States full prescribing information, please
visit www.ELOCTATE.com.

About ALPROLIXALPROLIX® [Coagulation Factor IX
(Recombinant), Fc Fusion Protein], the first recombinant clotting factor
therapy with prolonged circulation in the body, is approved in the
United States, Canada, Australia and Japan. It is indicated in the
United States for the control and prevention of bleeding episodes,
perioperative (surgical) management and routine prophylaxis in adults
and children with hemophilia B. ALPROLIX is not indicated for immune
tolerance induction therapy, which is a treatment for people with
inhibitors, and should not be used in individuals with a known history
of serious allergic reactions. ALPROLIX was developed by fusing factor
IX to the Fc portion of immunoglobulin G subclass 1, or IgG1.
It is believed that this enables ALPROLIX to use a naturally occurring
pathway to prolong the time the therapy remains in the body.

Common adverse reactions (incidence of greater than or equal to 1
percent) from the registrational B-LONG study were headache and oral
paresthesia (an abnormal sensation in the mouth). For additional
important safety information, and the United States full prescribing
information, please visit www.ALPROLIX.com.

About BiogenThrough cutting-edge science and medicine,
Biogen discovers, develops and delivers worldwide innovative therapies
for people living with serious neurological, autoimmune and rare
diseases. Founded in 1978, Biogen is one of the world’s oldest
independent biotechnology companies and patients worldwide benefit from
its leading multiple sclerosis and innovative hemophilia therapies. For
more information, please visit www.biogen.com.
Follow us on Twitter.

About SobiSobi is an international specialty healthcare
company dedicated to rare diseases. Sobi’s mission is to develop and
deliver innovative therapies and services to improve the lives of
patients. The product portfolio is primarily focused on Haemophilia,
Inflammation and Genetic diseases. Sobi also markets a portfolio of
specialty and rare disease products for partner companies across Europe,
the Middle East, North Africa and Russia. Sobi is a pioneer in
biotechnology with world-class capabilities in protein biochemistry and
biologics manufacturing. In 2014, Sobi had total revenues of SEK 2.6
billion (USD 380 M) and about 600 employees. The share (STO: SOBI) is
listed on NASDAQ OMX Stockholm. More information is available at www.sobi.com.

Biogen Safe HarborThis press release contains
forward-looking statements, including statements about the potential
benefits and efficacy of ELOCTATE and ALPROLIX. These statements may be
identified by words such as “believe,” “expect,” “may,” “plan,”
“potential,” “will” and similar expressions, and are based on our
current beliefs and expectations. Drug development and commercialization
involve a high degree of risk. Factors which could cause actual results
to differ materially from our current expectations include the risk that
unexpected concerns may arise from additional data or analysis,
regulatory authorities may require additional data or information or
further studies, or may fail to approve, or refuse to approve, or may
delay approval of our drug candidates, or we may encounter other
unexpected hurdles. For more detailed information on the risks and
uncertainties associated with our drug development and commercialization
activities, please review the Risk Factors section of our most recent
annual or quarterly report filed with the Securities and Exchange
Commission. Any forward-looking statements speak only as of the date of
this press release and we assume no obligation to update any
forward-looking statements, whether as a result of new information,
future events or otherwise.